For people stuck on the last level, every once in a while, the horizontally moving spike ball is timed with vertically moving ones, just as it moves away again, then jump again in the middle to avoid it when its coming back, then you should just have a clearing to make it through, hope this helps !
seems like we are alot of people here who misunderstood the point of the game, it doesnt matter if you keep the boxes or whatever, it only gives you extra points! So if you want points its about keeping those boxes on.
oh and please dont downvote comment before just becouse you disagree, the downvoting was supposed for comments that is irrelevant, not becouse he means something you dont mean.